ok, so you CAN land 121+3 from b3 "anywhere".....but theres a catch, you gotta do the b3 from point blank range, which isnt really where you want to be using that normal from.
im sure it is, but I can't consistently land it in practice mode even so it'll take some time to get the muscle memory down. you're much much better off just doing neutral jump 2 into the spear string if you have the KB